Ricochet and Penetration of Fast Moving Projectiles

Hello, I'm currently carrying out a project, and my chosen topic is ricochet and penetration. I am currently attempting fruitless research into the subject.

I was wondering if anyone was aware of any scientific papers/books that gives any equations regarding the penetration of surfaces of finite thicknesses, or any adaptation of such things within a game, and any papers/links to how they work. Also anything that explains how the material properties effect the angle at which a projectile would ricochet rather than penetrate.

I am writing a system to simulate this, and I cannot find any clear resources, though it might be me being stupid, coupled with sleep deprivation.

The projectile is non-deforming sphere, has a defined mass and diameter.